In contemporary societies, advertising operates as a fundamental instrument of economic communication and plays a significant role in shaping consumer decision making. When distorted, advertising may undermine public trust and disrupt transactional justice. This study examines misleading commercial advertising and analyzes how civil liability is defined and enforced within the legal framework of the European Union. The research adopts a descriptive analytical methodology based on the examination of European Union legal instruments, particularly Directive 2005/29/EC and its subsequent amendments, together with an analysis of the case law of the Court of Justice of the European Union. The findings indicate that European Union law structures civil liability for misleading advertising around principles such as professional diligence, legitimate consumer reliance, information transparency, and the objective standard of the average, well informed and reasonably observant consumer. Within this framework, the establishment of liability does not depend on proof of personal fault. Rather, the mere capacity of an advertising practice to influence a consumer’s economic decision is sufficient. The Court of Justice further emphasizes the materiality of information and the holistic assessment of advertising messages when distinguishing legitimate competition from commercial deception. Overall, this legal model transforms ethical standards into binding civil obligations system.